| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> |
| */ |
| |
| #ifndef __ASM_CPUFEATURE_H |
| #define __ASM_CPUFEATURE_H |
| |
| #include <linux/log2.h> |
| #include <asm/hwcap.h> |
| |
| /* |
| * Due to the fact that ELF_HWCAP is a 32-bit type on ARM, and given the number |
| * of optional CPU features it defines, ARM's CPU hardware capability bits have |
| * been distributed over separate elf_hwcap and elf_hwcap2 variables, each of |
| * which covers a subset of the available CPU features. |
| * |
| * Currently, only a few of those are suitable for automatic module loading |
| * (which is the primary use case of this facility) and those happen to be all |
| * covered by HWCAP2. So let's only cover those via the cpu_feature() |
| * convenience macro for now (which is used by module_cpu_feature_match()). |
| * However, all capabilities are exposed via the modalias, and can be matched |
| * using an explicit MODULE_DEVICE_TABLE() that uses __hwcap_feature() directly. |
| */ |
| #define MAX_CPU_FEATURES 64 |
| #define __hwcap_feature(x) ilog2(HWCAP_ ## x) |
| #define __hwcap2_feature(x) (32 + ilog2(HWCAP2_ ## x)) |
| #define cpu_feature(x) __hwcap2_feature(x) |
| |
| static inline bool cpu_have_feature(unsigned int num) |
| { |
| return num < 32 ? elf_hwcap & BIT(num) : elf_hwcap2 & BIT(num - 32); |
| } |
| |
| #endif |
